Model output discussion - proper cold spell inbound?

[Man With Beard]

45 minutes ago, Catacol said:

Dont fret. I'm immune... but anyway I doubt NW have put a laughing response on there to represent sarcastic negativity so we can all assume it is a laugh of happy support!

Catacol, thanks for your posts today and actually thanks for all your posts during the winter - in my books you have been the top poster throughout this season, making complex things very easy to understand - I've noted, particularly around New Year, that you've taken some pretty unfair criticism, so I'm really glad to see you getting some credit at last, and thank you for keeping on going with this forum.

What I really enjoy is seeing a theory tested out and I'm really looking forward to seeing if what you and Chino are going on about becomes reality in 10 to 20 days time.

 

[ukpaul]

1 hour ago, K9 said:

Fair point but I can assure that the Pennines has had snow cover for the past few days here in Gods own county of West Yorkshire so that sort of contradicts the whole post,unless of course you're referring to 'new snow cover'?..if so many apologies ..anyway ..back to the models !!!

Must be very high up, there was snow visible until this morning but it had gone by the end of the day up on the tops. Nothng lying down here in the valley, of course.  So the chart looks fairly accurate for this area in the far west of West Yorkshire.

[Daniel*]

Some of the best posts I’ve ever seen on this forum. This is what it’s all about! It has been a very long time seen I’ve excitement from the ‘experts’, and it’s reassuring to hear it from them as I’m feeling it too even though I don’t understand throughly understand these processes I know in a basic sense, it’s looking as good as it can be almost. 

QTR on GFS 18Z it looks - Azores high bye indeed RIP  

 

Edited February 5, 2018 by Daniel*

[Mucka]

Very flat UKMO/GFS Ops this morning so barring a dramatic reversal (which is still possible if the models are not sniffing out trough disruption) it looks like we will be relying on PM air to bring cold after this current snap, at least until we can get rid of the Azores high spoiler.

[FENDER.]

And we could still be waiting this time next month lol.    This was supposed to be the big week for cold and snow, now its possibly next week or perhaps the final third of February.  Its just never quite come off does it ?

Looking the the charts for the next 7 days it looks cold and mainly dry to me. there will be bits of snow around particularity in the SE, but the day temperatures of between 3-5c, will make settling snow unlikely, except on high ground.  .   . 

[Weather-history]

26 minutes ago, Fender.. said:

Check out the UKMO GFS Ops  see what you think

I see those high pressure cells again around Newfoundland, which seems to be a feature of this winter,  which means the airmasses are coming off Labrador, Canada again. It's a very cold airmass over there so I suspect tropical airmasses will be limited. The airmass that comes after the front on Tuesday, is such an airmass.

Edited February 5, 2018 by Weather-history

[Banbury]

49 minutes ago, Fender.. said:

Check out the UKMO GFS Ops  see what you think

The GFS op is st the high end on several days of the run some support but no point in saying a downgrade until you look at the ENS

[Banbury]

25 minutes ago, Weather-history said:

I see those high pressure cells again around Newfoundland, which seems to be a feature of this winter,  which means the airmasses are coming off Labrador, Canada again. It's a very cold airmass over there so I suspect tropical airmasses will be limited. The airmass that comes after the front on Tuesday, is such an airmass.

Correct and the HP is close by which is all that counts this far out . 

[timboy666]

No sure its a downgrade at that time frame   

[Troubleatmill]

24 minutes ago, Banbury said:

The GFS op is st the high end on several days of the run some support but no point in saying a downgrade until you look at the ENS

Agree with you, and looking through the GEFS ens nothing has changed this morning. This week cold as we know, week two mixed bag of PM air and warm sectors then a steady number of ens are sniffing at some quite eye watering HLB for winters lap of honour. Prety good 00z over all. Lets see if the ECM starts anything right at the back of its run but think T240 is still a little too today, we'll see soon enough 

Edited February 5, 2018 by Nicholas B

[karlos1983]

I think the very well written posts from Chio and Catacol yesterday evening explain a lot. So either you haven’t read them, are rather oddly ignoring them or you are just here to ruin the thread for the majority. 

Gett well in the reliable now this warming event

 

[Troubleatmill]

25 minutes ago, Nicholas B said:

Agree with you, and looking through the GEFS ens nothing has changed this morning. This week cold as we know, week two mixed bag of PM air and warm sectors then a steady number of ens are sniffing at some quite eye watering HLB for winters lap of honour. Prety good 00z over all. Lets see if the ECM starts anything right at the back of its run but think T240 is still a little too early today, we'll see soon enough 

Delete 

Edited February 5, 2018 by Nicholas B

[Chevron12345]

4 hours ago, Daniel* said:

Some of the best posts I’ve ever seen on this forum. This is what it’s all about! It has been a very long time seen I’ve excitement from the ‘experts’, and it’s reassuring to hear it from them as I’m feeling it too even though I don’t understand throughly understand these processes I know in a basic sense, it’s looking as good as it can be almost. 

QTR on GFS 18Z it looks - Azores high bye indeed RIP  

 

Quick Trop Response? Is it on that chart or are you just guessing? PV looks pretty organised to me.

I mean, I didn't any charts would be showing the effects of a SSW for a number of days yet.

Edited February 5, 2018 by Chevron12345

[mb018538]

Ensembles:



Big divergence showing up at day 7 - which means if they can't agree on a solution at that timescale, anything else is pure conjecture. The OP is one of the miler and wetter runs, so no need to get too worried!

[bluearmy]

The gefs zonal mean continues to show little sign of any flow reversal in the trop. Some members are certainly there or there abouts. Take into accont that the lowish res of the gefs in the strat maybe not such a good indicator of downwelling events 

Edited February 5, 2018 by bluearmy

[Leon1]

I don't know much about reading these charts, but are we doing well or not so well for a snow event during Feb or march

[Summer Sun]

UKMO extended shows a northwesterly setting this morning

[Paul_1978]

12 hours ago, bluearmy said:

Quick trop response 

Aha, QTR not ‘qtr’! I was thinking something to do with a quarter! 

Anyway, this morning’s output not great at face value, so it’s a case of waiting for the SSW to start having an effect on the NWP. Looks like the models will be volatile for a few days yet until they suss out what’s going on. 

[mountain shadow]

17 minutes ago, Leon1 said:

I don't know much about reading these charts, but are we doing well or not so well for a snow event during Feb or march

It's snowing in the South East right now and it will be snowing in the North West this evening.

Any strat influence is still past mid month and out of model range. 

[Singularity]

I think it's fair to interpret that GFS is not modelling a quick downward propagation (i.e. quick tropospheric response; QTR) of the SSW event, but it is important not to make the mistake of believing what the models are showing you at more than a week's range (if even that). 

In fact, that's a valid approach in a normal situation, let alone with the SSW involved.

Liking the adjusting angle of the flow on the ECM 00z with height rises to the E and NE looking increasingly 'available'.

[bluearmy]

Extended Eps beginning to look more w euro trough whIch isn’t the best to advect cold west 

 

[mb018538]

23 minutes ago, bluearmy said:

Extended Eps beginning to look more w euro trough whIch isn’t the best to advect cold west 

 

Nope, and sadly a SSW doesn't always equal jackpot does it. All depends on where the pieces of the puzzle fall - some places will go into the freezer, others will be warmer than normal. We will just have to wait a few more days before this starts to emerge.

[Frosty.]

22 minutes ago, bluearmy said:

Extended Eps beginning to look more w euro trough whIch isn’t the best to advect cold west 

 

At least it's not a dreaded euro slug sucking the life out of what remains of this winter..anyway, I'm looking forward to the cold zonality the latest models are showing plus I'm very excited about what the models aren't showing at the moment!!

[TEITS]

I have been keeping an eye on the GEFS SLP Mean for Iceland because to me around the 19th Feb we could well see the development of a Greenland HP.

The mean continues to rise and now stands a 1015mb. The 0Z GFS was clearly much lower than the mean.

Until then though I feel after this week the weather will turn more unsettled, less cold, less snow than some are suggesting including the Met O.

[bluearmy]

57 minutes ago, mb018538 said:

Nope, and sadly a SSW doesn't always equal jackpot does it. All depends on where the pieces of the puzzle fall - some places will go into the freezer, others will be warmer than normal. We will just have to wait a few more days before this starts to emerge.

Given the issues of strat/trop coupling and the modelling of the strat being at lower res with less layers, I think we need to be circumspect re nwp for later next week and beyond